Reconfigurable optical add/drop multiplexer and procedure for outputting optical signals from such multiplexer

Abstract

A reconfigurable optical add drop multiplexer (ROADM) includes local interfaces at which optical signals of different wavelengths are locally input into the ROADM, and a network interface configured to connect the ROADM to a network from which multiplexed optical signals of different wavelengths are transmitted to the network. In a first configuration, the ROADM is configured to transmit from the network interface to the network multiplexed signals of different wavelengths having a first minimum frequency difference. In a second configuration, the ROADM is configured to transmit from the network interface to the network multiplexed signals of different wavelengths having a second minimum frequency difference. The second minimum frequency difference is greater than the first minimum frequency difference. This arrangement reduces the power of four wave mixing cross products produced when optical signals of three wavelengths are multiplexed and transmitted from the ROADM to NZDSF or DSF fiber types.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit of U.S. Provisional Application No. 60 / 924,732 filed May 30, 2007.INCORPORATION BY REFERENCE[0002]The present application incorporates by reference the entire contents of U.S. Provisional Application No. 60 / 924,732 filed May 30, 2007.BACKGROUND[0003]1. Field[0004]Example embodiments disclosed herein relate in general to the field of wavelength division multiplexing and more particularly to a multifunctional and reconfigurable Dense Wavelength Division Multiplexing (DWDM) optical node. Example embodiments disclosed herein also relate to an optical node and an optical network including a reconfigurable optical add drop multiplexer core device.[0005]2. Related Art[0006]Wavelength Division Multiplexing (WDM) and Dense Wavelength Division Multiplexing (DWDM) are technologies that enable a multitude of optical wavelengths of differing frequencies to be transported over a single optical fiber. A DWDM network is...

AI Technical Summary

Benefits of technology

[0012]One or more of the example embodiments provide a ROADM including a plurality of local interfaces at which optical signals of different wavelengths are locally input into the ROADM, and a network interface configured to connect the ROADM to a network from which multiplexed optical signals of different wavelengths are transmitted to the network. In a first configuration, the ROADM is configured to transmit from t

Problems solved by technology

As a result, while they are reconfigurable, they are not multifunctional, which limits their usefulness.

First, the optical power of the generated cross products depletes the optical power of the optical signals transmitted on the network that carry information, and therefore FWM cross products affect channel OSNR (optical signal-to-noise ratio), resulting in a larger than normal power loss over the span of a fiber optic cable.

Second, cross products of exactly the same wavelength as optical signals carrying information on the network create coherent interference / crosstalk and produce a significant OSNR margin reduction, which can lead to traffic outages.

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